Apparatus for making metal-cased tubes.



J. W. EARLE & A. BOURNE.

APPARATUS FOR MAKING METAL GASED TUBES.

APPLICATION FILED JUNE 19, 1909. 946,022 Patented Jan. 11, 1910.

3 SHEETS-SHEET 1.

w. P gw/ .7540 aw J. W. EARLE & A BOURNE. APPARATUS FOR MAKING METAL GASED TUBES.

APPLICATION FILED JUNE 19, 1909.

Patented Jan. 11,1910.

3 SHEETS-SHEET 2.

V 70 S WIT/VESJES //V [A] J. W. EARLE & A. BOURNE. APPARATUS FOB. MAKING METAL GASED TUBES.

APPLICATION FILED JUNE 19, 1909.

. 946,022'- Patented Jan. 11, 1910.

3 SHEETS-SHEET 3.

W/ T/VESS E6 UNITED sTA'rnsr 'rENr OFFICE.-

.J'OHN WILLIAM EARLE AND ALFRED BOURNE. OF BIRMINGHAM. ENGLAND; SAID BOURNE ASSIGNOR- TO SAID EARLE.

APPARATUS FOR MAKING METAL-CASED TUBES.

Specification of Letters Patent.

Patented ban. 11, 1910.

Application filed June 19. 1909. Serial No. 503,090.

To altwhom 'it may concern.

lie it known that we, JOHN \VILLIAM .EAnLn and ALFRED Bommn, subjects of Y provements in Apparatus for Making'Metal- Cased Tubes, of which the following is a specification.

This invention has for its object the ex-v peditious production atsmall cost of metal cased tubes of the type in which a locking strip is inserted between the case and the inner tube for securing together the edges of the case.

The invention relates to the features of construction and combination and arrangement of'parts hereinafter set forth and particularly described in the claims.

Referring to the three accompanying sheets of explanatory drawings ;F1gures 1, 9. and 3 are respectively side elevation, plan and sectional side elevation of tools or dies adapted in accordance with this invention for producing tube: of the type aforesaid.

'-. In Figs. 1 and 2 the case, locking strip, and

inner tube are also shown in position, but in Fig. 3 the case and locking strip are omitted for clearness. Fig. 4 is a side elevation and Flg. 5 a plan of the guide piece for guiding the locking strip into position; Figs. (3 and 7 are elevations taken at opposite ends of the guide piece while Fig. 8 is a cross section on A A Fig. 4. Figs. 9 to 14 illustrate the shapes of successive portions. of the dies at the lines B to G (Fig. 1) and the corresponding shapes of the tube portions pass ing therethrough. Figs. 4 to 14 are drawn to a larger scale than Figs. 1 to 3.

The same reference letters in the different views indicate the same parts.

In carrying the invention into elfect as illustrated the bending and drawing of the case strip a on to the ordinary inner tube 1) is efi'ected'by adie which for convenience is made in sections united or secured in the necessary alinement by screws, a holder, or

any other suitable means.

The front section 0 of the die is provided with a U-shaped channel which is bell mouthed at its outer end and tapered in the direction of its length. Such section is covered by a plate (Z having grooves c with central ridge 0 formed on its underside for guidin the edges .of the case strip and gradua ly drawing them together. The

section of the die.

guide piece 18 made convex to correspond cover plate (Z does not cover the whole of the section 0 but leaves a portion at its rear edge exposed as shown in Figs. 1 to 3. The shape of the frontend of the die aperture in the section 0 at the position corresponding to line B. B. (Fig. 1) is shown at Fig. 9 while the shape at or near the rear of that section (line (7. C. Fig. 1,) is shown at Fig. 10.

The middle section f of the die contains a tapered aperture the configuration of which changes from an oval form as shown at Fig. 1 (line D. D.- Fig. 1) at one end to the approximately circular form shown at Fig. 12 (line E. E. Fig. l) at the other end. Aloug the upper side of such aperture. a central ridge is provided for the purpose hereinafter described. Therear section ity of the die comprises an aperture which passes from the shape shown at Fig. 13 (line F. F. Fig. 1) at its front end to the exactly circular form shown at Figflat (line G. G. Fig. 1.) at its rear end, the latter corresponding to the dimensions of the finished tube. Each section is bell mouthed at. the entrance to its aperture to avoid a sharpv ridge between the sections.

In conjunction with the front and middle portions and (l of the die there is arrangeiil a loose guide piece At one. extremity of such piece is formed an upwardly projecting shoulder adapted to enter a slot 7. inthe plate (Z aforesaid. for preventing the piece from being drawn forward with the tube.

The portion of the guide piece which. enters the (he ls-tapered 1n the direction of its length and is formed with a slot 1 at its forward extremity to pass along eachside of the ridge g above referred to in the middle On its upper side the with the shape of the die aperture in which it lies, while at its underside it is made concave to correspond with the circumference of the inner tube 7). Along the underside a slot m is also formed to receive the locking strip a of the tube.

- Prior to forming a tube, the front end of the inner tube 7) is inserted through the die together with a portion of the 'case strip a and the locking strip a which is preferably shaped previously to a channel section. In some-cases the locking strip may be shaped by the guide piece 2'. The said guide piece is also-placed 1-n position. On drawing the inner tube, case and locking strip through the die, the sides'of the case strip a are gradually closed over on to the inner tube. The edges are also turned inward by the action of the ridge g in the central section of the die and caused to enter the locking strip which is guided into position by the slot m, in the underside of the guide piece 71. Subsequently the edges of the two strips are closed tightly together, and the case further closed on to the inner tube. By the action of the last section of the die, the tube is completed. The successive stages in the formation of the complete tube are clearly shown by the sectional views at the right hand sides of the views showing the dies in Figs.,9 to 14. The inner tube 1) is initially circular in section, but in the last portion of the die it becomes flattened slightly in the neighborhood of the joint in the case. No special provision is therefore required in the preparationof the inner tube to accommodate the'additional thickness of the case at the joint caused by the inturned edges of the case and the locking strip. The configuration of the outer periphery of the fin ished tube is circular throughout. In the drawings the thickness of the case is exaggerated for clearness of illustration. In practice the extra thickness of metal at the joint and the flattening of the inner tube at that part is scarcely appreciable to the eye.

The invention is not limited to cylindrical tubes but may be applied to tubes of rectangular or any other desired cross section. By the means and procedure hereinbefore described tubes of superior finish or appearance can be readily produced, and as thinner cases can be employed than is ordinarily permissible the tubes can be manufactured at correspondingly smaller cost.

\Ve claim;

1. In means for producing metal cased tubes, the combination comprising a die having an aperture adapted to close a case strip around an inner tube, simultaneously withthe drawing of the said strip and tube together through the die, and a guide piece whereby a locking strip is directed into position between the inner tube and case strip for en agi.g the ed es of the latter, substantia ly as describe 2. In means for producing metal cased tubes, the combination comprising a die pro vided with an aperture the shape of which changes continuously from an oval section at one end to a circular section at the other end, a central ridge extending along a portion of the die, and a guide piece slotted at its under side, substantially as described.

3. In means for producing metal cased tubes, the combination comprising a die rovided with an aperture the shape of w ich continuously changes from an oval section at one end to a circular section at the other end, a central ridge extending along and made integrally with a portion of the die, and a loose guide piece slotted at its under side and adapted at its upper side to abut against the die for preventing longitudinal movement of the guide piece with the work, substantially as described.

at. In means for producing metal cased tubes, the combination comprising a die composed of sections with apertures in alinement, one of the sections being formed with' a trough shaped aperture, a cover plate at- .tached to the section with trough shaped aperture and adapted to form therewith an aperture of oval section with a central ridge, a central ridge formed with and extending along a portion of the aperture in the other die sections, a loose guide piece slotted at its forward end and along its underside and shaped at its upper and lower surfaces to a convex and concave configuration respectively, and. a projection formed with the guide piece for abutment against a slotted portion of the cover plate, substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing Witnesses. I

JOHN WILLIAM EARLE. ALFRED BOURNE. Witnesses:

JoHN MORGAN, IIARRY DAVIS. 

